Yes, I also hate that they do that, and this is what usually makes me suspicious as well. But:
a) This could mean there are many more “quiet” guys out there making fortunes without selling anything and without being known. This could be someone like the OP mentioned here initially.
b) The guy I mentioned, knows that he is reaching his capacity and won’t be able to continue multiplying his account much longer. He’s already going in with $50k+ on some penny stocks where stakes are getting higher and higher. It’s also very stressful, so after a while many former traders start offering some training. And actually training can become more profitable than trading, so it’s a business like all others. Another guy, Ross Cameron of Warrior Trading shows how he’s making, say $500k in a year from trading, but now employs several more traders as “trainers” and has 550K YouTube subscribers, where I suspect he may be making several $million from training, per month...
Many people are also business minded and building a training organization becomes their goal when they see what others do. They have to acquire at least some trading skills to achieve that.